1. Field of the Invention
The present invention relates to disk drives. More particularly, the present invention relates to a disk drive executing a manufacturing program internally by executing disk commands through a vector.
2. Description of the Prior Art
A disk drive may be designed to process vendor specific commands (VSC) used by vendors (such as disk drive manufactures) to test and configure the disk drive during manufacturing. In the past, the manufacturing program was developed using a programming language (e.g., assembly, C or Cow) and executed by an external test system known as a single plug tester (SPT) communicating with the disk drive over a host interface. In order to increase the manufacturing throughput, the number of SPTs must be increased which is expensive due to the “intelligent” circuitry employed within each SPT.
U.S. Pat. No. 5,282,501 discloses a disk drive which executes a test program internally thereby avoiding the expense of an external test system. However, the test program executed within the disk drive comprises a sequence of standard read/write commands similar to the commands sent by a host system. It would be impractical to implement many of the manufacturing programs using read/write macros as disclosed by the '501 patent. For example, it would be impractical to implement the defect scan which scans the disk for defective sectors and logs pertinent statistical data in an initial burn in (IBI) log stored in a system file on the disk. The IBI log is then used to create a defect list for mapping defective sectors to spare sectors.
There is, therefore, a need to execute manufacturing programs for a disk drive while avoiding the expense of external test systems.